Abstract：Taking aluminum sulfate solution as coating agent, the effect of p H value, temperature, aging time and coating quantity on the dispersion stability of alumina-coated titanium dioxide was studied through the parallel flow precipitation process. The surface property, microstructure and component of the coated samples were characterized by Zeta potential analyzer, TEM and ICP-MS.The results show that the optimal conditions for coated samples with high dispersion stability are as follows: the p H is 9, the temperature is 70 ℃, the ageing time is 2 and the coating quantity is 3.2%. The specific surface area of coated titanium dioxide is increased from 6.73 m2/g to 18.28 m~2/g and the oil-absorption value is improved from 19.88 g/m L to 32.46 g/m L under the optimal conditions. On the other hand, the flocculent coating layer on the coated samples is uniform and continuous. The surface property,the electrostatic repulsion between particles and the dispersion stability in aqueous dispersion system were improved remarkably.

Keywords: titanium dioxide; dispersion stability; coating; aluminum oxide